To simplify the structure of a device and make it compact in an in-pipe treating machine of a buried pipe, including: a device body movable in the buried pipe; a turning shaft rotatably supported in the center of the device body; a support fitted to the turning shaft to slide in the axial direction and not to rotate relatively, and supported to the device body to slide in the axial direction and to rotate relatively; an in-pipe treating means mounted on the tip of the support to make a treatment for the interior of the buried pie; a forward and backward drivingmeans for driving the support forward and backward to the device body; and a rotary driving means for turning the turning shaft.

This rotary driving means Dr includes: a motor M having an output shaft 6 parallel to the turning shaft J and disposed in the device body 1; and a spur gear train G for rotating the turing shaft J interlocking with the output shaft 6 of the motor M. A brake pad 7 is provided in pressure contact with the outer peripheral part of some gear G1 of the spur gear train G, and a brake means B for holding the turning shaft J in an arbitrary turning position is disposed on the device body 1.